Windows Server 2012 and SMB2

All the settings on the NetApp side were default, so SMB2 was enabled. Every attempt to access a CIFS share from w2k12 led to the server reboot. I now disabled SMB2 (options cifs.smb2.enable off) & everything works like a charm.

Is it something specific to simulator maybe, or does w2k12 'dislike' SMB2 on ONTAP (8.1.1)?